Stabilized composition



Aug. 23, 1949. B, B. MCHAN 2,4%,583

STABILIZED COMPOSITION Filed April 11, 1946 PEFX/E VALUE @ZET Patented Aug. 23, 1949 s'rAmzeD comemos Brack B. McHan, Quincy, lll., assignor to Calcium Chicago, Ill., a corpora- Carbonate Company, tion of Illinois Application April 11, 1946; Serial N0. 661,247

Claims.

This invention relates to improvements in the stabilization of chemical compounds and is a continuation-impart of my allowed copending application, Serial No. 478,938, led March 12, 1943, now Pat. No. 2,403,010, issued July 2, 1946. More particularly, it pertains, for example, to

the stabilization of calcium compounds. such as limestone, to be used as an ingredient in food products, or the like, without fear that it will materially destroy the vitamin content or develop rancidity in the remaining ingredients, and this is a principal object of the invention.

Calcium carbonate, in the form of ground limestone, is a commonly used ingredient in feed mixtures. It is used in percentages varying from 1 to 5 per cent. Calcium carbonate is a necessary component of the diet. The addition of calcium carbonate to food is deemed necessary in order to maintain the correct balance or. ratio of calcium and phosphorus and to insure the normal development of the skeletal structure as well as. to maintain the necessary balance of calcium in the blood stream and the other organic portions of the normal animal structure.

To supply the necessary calcium requirement it is common practice of feeders of all classes of livestock to introduce into the mixed feed a' necessary quantity of calcium. This is usually introduced in the form of pulverized limestone. It is also conventional practice to fortify feed. products with various vitamin concentrates in order to insure a necessary amount of these very l important ingredients being present at all times.

Vitamin A may be added in the form of carotene, various sh oils, or alfalfa meal. Vitamin D is usually added through the medium of one of the iish liver oils, or by means of any other suitable vehicle. Most of the common forms of feed g stuff, such as alfalfa hay or meal, corn meal (especially yellow corn meal),I grains and grain products,` carry varying percentages of various vitamins and oils. Vitamins are Very readily destroyed by processes of oxidation. -As an example, the vitamin A content of alfalfa meal will be reduced as much as 50 per cent in less than two months time due to oxidation of the vitamin A molecule.

The oils present in the natural feed stuffs alsoundergo processes of oxidation resulting in the development of varying degrees of rancidity. The rancid odor developed through oxidation of theoils impairs the attractiveness and palatability of the food, and greatly reduces its .biological activity by the accompanying destruction of vitamins. VThe development of rancidity is accompanied by the development of substances known as pel-oxides; these peroxides in turn further oxldize the vitamins, oils, and natural enzymes of feed materials. l

Generally, it is an object ofthe invention to overcome the foregoing difficulties and disadvantages by eilectively lowering the oxidation-reduction potential of useful compounds, both lnorganic as well as organic, the latter comprising,

in particular, animal and vegetable products.

More specifically, it is an object of the invention to provide a composition of matter and method of 'treatment for producing the same comprising calcium carbonate and a chemical substance or compound adsorptively combined therewith over its reactive area, such a material preferably comprising sodium thiosulfate; or a combination of sodium i'li'iosulfate and sodium hydroxide; or a combination of sodium thiosulfate, sulfur, and sodium hydroxide; and thereafter reacting one of such substances or a corn'- pound thereof with the calcium carbonate to provide a composition having as its essential property an adsorption isotherm of such characteristic that oxygen adsorbed .by the calcium carbonate is replaced and further adsorption of oxygen by the carbonate is prevented, to the end that the composition, when used, for example, as an ingredient of food, will not destroy vitamins nor initiate rancidity development.

'Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the product possessing the features, properties, and the relation of constituents, which are exemplified in the following detailed disclosure, and the scope of the application of which Will be indicated in the claims.

The sole figure is a graphic illustration of the effect of the various reagents herein, singly and in combination, on theperoxide value showing the peroxide development plotted against time in days and depicts the high oxidizing capacity of untreated calcium carbonate and the reducing effect of each of the reagents when used singly, and still further the great reduction in oxidizing value when used in combination.

The problem of rancidity development and destruction of vitamins in food products has long confronted the industry and solutions thereto deed, a contrary view has inevitably obtained. The molecule of calcium carbonate is an ex.- tremely stabile one with the oxygen molecules so tightly bound that they would not lbe transferred in any ordinary processes. of oxidation. This statement is susceptible to both chemical and thermodynamic proof. Hence, this material has heretofore been eliminated as being among one of the chief causes that give rise to the problem.

The present invention, however, is based on my discovery that calcium carbonate is the primary cause of vitamin destruction and rancidity development in this connection. Ihave found that during the processes of grinding and attrition of the calcium carbonate, the surfaces of the particlesfpresented unsaturated chemical bonds which picked up, at activated points, oxygen atoms from the air. Also, that the oxidizing action of the adsorbed oxygen on the surface of the carbonate particles could completely be nullied or replaced by some substance preferentially adsorbed over the oxygen, and that the chemical nature of this substance must have an adsorption isotherm that would effectively prevent the carbonate from adsorbing further oxygen on storage.

It was further observed that on many of the surfaces of the calcium carbonate particles the oxygen atom may be closely compacted and in a highly reactive state. When a particle of calprocess of grinding. This caused a drop in the oxidation-reduction potential of the calcium carbonate suiilciently low effectively to inhibit its oxidizing reaction on such substances as vitamins and oils. Vitamins and vitamin carrying products when mixed with calcium carbonates thus treated remained 70 per cent to 80 per cent stabile up to six months time, whereas in untreated calcium carbonate they would be completely destroyed in less than a. week. Oils and food products containing oils or fats when mixed with the treated calcium carbonate retained their original fresh odor without any 'development of rancidity for over a year.

With respect to the relative weights of materials used, it has been found that sodium thiosulfate is desirably effective in percentages ranging from 0.1 vper cent to 0.5 per cent, which is equivalent to two pounds and ten pounds of sodium thiosulfate per ton of limestone respectively. While this is a preferred range, desirable results' have been secured from percentages varying from 0.01 per cent up to and in excess of 1.0 per cent.

Such processes actually have been practiced with sodium hydroxide, sulfur and sodium thiosulfate, singly and in combination. It is deemed unnecessary to set forth further examples. However, reference to the following tables will provide any supplementary information that is necessary:

TABLE I Raneidity development in 1% A-D oil mixtures elect of sulfur', sodium thiosulfate and sodium hydroxide on peroxide values Peroxide Value After Number of Days Shown Reagent Y Control 14. 9 17.1V 16. 8 12.6 8. 4 5.6 4. 5 3. 4 1. 7 1.6 l. 5 0.2% Sodium Thiosulfate 0.4 0.2 0.2 5.0 6.8 2. 7 2.6 2.0 1.6 1.9 1.4 0.2% Sodium Hydroxide 0.8 1.3 1.8 2. 3 2. 7 2.6 3.1 2. 2 2.8 2.8 2. 8 0.2% Sodium Thiosulfatc+0.2% Sodium Hydroxif.e 0,4 0.1 0.0 0.0 0. 2 1.2 2.4 2. 7 1.1 0.9 1.0 0.1% Sodium Thiosulfate+0.2% Sulfur+0.2% Sodium Hydroxide 0.0 0.0 0.0 0.0 0.2, 0.6 0.2

cium carbonate, carrying its charge of adsorbed TABLE II oxygen atoms, comes into contact with an oxidizable substance, these oxygen atoms are transferred and the substance oxidized. It lhas also been noted that very quickly after mixing an oxidizable substance with calcium carbonate, such, for example, as Vitamin A, fish oils, or carotene, that 90 per cent plus will be oxidized. This, however, does not neutralize the oxidizing capacity of the calcium carbonate as thesev activated points on the crystal simply pick up more oxygen atoms from the air and again transfer them to oxidizable substances. This process goes on until the oxidizable substance has been completely saturated with oxygen.

As a result of these combined discoveries and observations the problem at hand has been solved by a process of subjecting the calcium carbonate to the action of a suitable stabilizing agent which, by adsorption, effectively will reduce the oxidation-reduction potential, either before, during or after grinding of the calcium carbonate. An actual process of treatment will now be described as set forth in the following example:

. EXAIVIPLE 1 Sodium thiosulfate, 0.5 per cent, was mixed Oxidation-reduction values for various reagents [EH=oxidution-reduetion potential (redox) From all of the foregoing uses, and others, it appears that any chemical compound or reagent, used .in accordance with the teachings of the present invention, and which possesses the property of a high degree of adsorption on limestone particles, that is, will have an adsorption isotherm of such characteristic that it would cause the replacement of adsorbed oxygen, and would effectively prevent any further adsorption of oxygen by the calcium carbonate particles, should act as an effective stabilizer.

The oxidation-reduction potential, or redox potential, in all cases was measured by means of a potentiometer and it should be noted that in order to secure the best results, a redox potential envases value of preferably around l-0.35 should not be exceeded.

It should further be noted that the present invention contemplates adaption to other fields of industrial usage. The property ofundergoing. spontaneous oxidation when exposed to the atmosphere is by no means peculiar to edible fats, but is exhibited also by many other substances of biological and industrial importance. For example, cases outside of the eld of the preservation of food are the aging or perishing of rubber, the formation of gum in gasoline, production of sludge in mineral, lubricating and transformer oils, and the oxidation and resinification of essential oils.

In addition to the foregoing, prevention of the development of rancidity and vitamin los and Y vitamin-carrying substances are important in the pharmaceutical trade as, for instance, the inclusion of vitamins in tablets or capsules where various substances are used as carriers.

The invention can also be adapted in the nem of paint and paint oils where many calcium carbonates when mixed with certain types oi oils accelerate the oxidation thereof. In addition to calcium carbonate, other nely ground powders, such as lithopone, white lead, titanox, China clay, and barytes, can thus be treated.

Since changes when carrying out the above process, and certain modications in the composition which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described. and all statements of the scope ofthe invention which, as a matter of language. might be said to fall therebetween.

Particularly, it is to be understood that in said claims, ingredients or compounds recited in the singular are intended to include compatible mixtures of such ingredients wherever the sense permits. Y

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A stabilized composition of matter comprising discrete particles of calcium carbonate and sodium thiosulfate as an oxidation-reduction potential reducing substance, said substance preferentially being adsorbed over oxygen reaction areas of said calcium carbonate.

2. A stabilized composition of matter comprising discrete particles of calcium carbonate and 0.1 per cent to 0.5 per cent of sodium thiosulfate as an oxidation-reduction potential reducing substance, said substance preferentially being adsorbed over oxygen reaction areas of said calcium carbonate.

3. A stabilized composition of matter comprising discrete particles of calcium carbonate and 0.01 per cent to 1.0 per cent of sodium thiosulfate as an oxidation-reduction potential reducing substance, said substance preferentially being adsorbed over oxygen reaction areas of said calcium carbonate.

4. A stabilized composition of matter comprising discrete particles of calcium carbonate having intimately admixed therewith a fraction of one per cent of sodium thiosulfate, and a fraction of one per cent of sodium hydroxide.

5. A stabilized composition of matter comprising discrete particles of calcium carbonate having intimately admixed therewith a fraction of one per cent of sodium thiosulfate, a fraction of one per cent of sodium hydroxide, and a fraction of one per cent of sulfur.

BRACK B. McHAN.

No references cited. 

